"The applicant is a child psychiatrist whose overall research objective is to understand the etiopathophysiology of common childhood mental disorders in order to identify more effective treatment and preventive strategies. The proposal is designed to provide the applicant with advanced interdisciplinary skills in brain imaging and neurophysiology. This will be necessary for the success of the proposed research as well as of future innovative projects, supporting the transition from mentored to independent researcher. The project aims to gain insight into the etiopathophysiology of Attention-Deficit/Hyperactivity Disorder (ADHD), one of the most common and impairing childhood mental disorders. Current ADHD treatment is symptomatic, not curative. Treatments targeting etiopathophysiological mechanisms may provide specific curative action. Preliminary data by the applicant’s group suggest that iron deficiency (ID) is a possible etiopathophysiological candidate in ADHD. The proposed research aims to extend these results comparing brain iron levels, estimated by a novel imaging approach (magnetic field correlation), in 20 children with ADHD and 20 healthy controls, and correlating them with measures of functional connectivity. Moreover, the unexplored correlation between brain iron and parameters from electroencephalogram, polysomnogram, and event-related potentials will be assessed in an additional sample of 20 children with ADHD. The project includes specific training in “Translational Developmental Neuroscience,” with a focus on brain imaging, at the Institute for Pediatric Neuroscience, New York University, NY, and training in neurophysiology at the Child Neuropsychiatry Unit, Verona University, Italy. The expected results have the potential to confirm the role of ID in ADHD, providing a strong rationale for large trials of iron supplementation. Considering the low cost of iron therapy and the high prevalence of ADHD, the proposal exhibits high public health relevance"